VISUAL AND OCULOMOTOR FUNCTIONS OF MONKEY SUBSTANTIA NIGRA PARS RETICULATA .2. VISUAL RESPONSES RELATED TO FIXATION OF GAZE
VISUAL AND OCULOMOTOR FUNCTIONS OF MONKEY SUBSTANTIA NIGRA PARS RETICULATA .2. VISUAL RESPONSES RELATED TO FIXATION OF GAZE
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DOI：
10.1152/jn.1983.49.5.1254
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发表时间：
1983-01-01
影响因子：
2.5
通讯作者：
WURTZ, RH
中科院分区：
文献类型：
--
作者：
HIKOSAKA, O;WURTZ, RH
描述了两种依赖于猴子注视的视觉反应。为了证明这些反应，将黑质细胞的反应与两种不同条件下相同视网膜位置的相同视觉刺激进行了比较：一种是当刺激出现时，猴子正在或曾经注视一个光点（注视条件）；另一种是，当刺激出现时，没有任何光点可供猴子注视（非注视条件）。当猴子没有注视另一个光点时，第一种类型的反应发生在一个光点上（非注视相关视觉反应）。在 155 个具有一些感觉或动眼神经反应的黑质细胞中，45 个细胞 (29%) 显示出这种类型的反应。反应是放电率下降，与刺激开始时间锁定（平均潜伏期，126 毫秒）。在非固定条件下测定的这些黑质细胞的视觉感受野很大，经常向对侧和同侧延伸40°。的视角。视野中央部分的刺激总是最有效的；对侧视野中的刺激通常比同侧视野中的刺激更有效。中央凹上存在的明显刺激通常与视觉固定有关，对于抑制视觉反应很重要。间隔时间越短，这些黑质细胞在非注视条件下的视觉反应越弱。经过多次试验后，反应逐渐减少。与猴子注视固定相关的第二种类型的反应是对猴子注视的光点偏移的反应（平均潜伏期，131毫秒）（注视相关的视觉失调反应）。在 154 个具有一些感觉或动眼神经反应的黑质细胞中，有 36 个细胞 (23%) 显示出这种类型的反应。他们中的许多人还具有非注视的偶然视觉反应。如果另一个位置出现故障，这种偶然的不响应在很大程度上会被抑制。只有当注视点消失而没有其他明显刺激时才会出现反应。随着从注视点偏移到视觉目标出现的时间增加，反应变得更大。这些黑质细胞对猴子将要注视的光点的出现或它所注视的光点的消失做出反应。它们可能发出视觉引导动眼行为的开始或终止的信号。
Two types of visual responses that are dependent on the monkey''s fixation of gaze were described. To demonstrate these responses, responses of substantia nigra cells were compared to the same visual stimulus with the same retinal location under 2 different conditions: one in which the monkey was or had been fixating on a spot of light when the stimulus came on (fixation condition), and the other in which no spot of light was present for the monkey to fixate on when the stimulus came on (nonfixation condition). The 1st type of response occurred to a spot of light when the monkey was not fixating on another spot of light (nonfixation-contingent visual response). Of 155 substantia nigra cells with some sensory or oculomotor responses, 45 cells (29%) showed this type of response. The response was a decrease in discharge rate that was time-locked to the onset of the stimulus (mean latency, 126 ms). Visual receptive fields of these substantia nigra cells determined under the nonfixation condition were large, extending both into the contralateral and ipsilateral sides frequently by 40.degree. of visual angle. A stimulus in the central part of the visual field was always the most effective; a stimulus in the contralateral visual field was usually more effective than 1 in the ipsilateral field. The presence of an overt stimulus on the fovea, which was usually associated with visual fixation, was important for the suppression of the visual response. The shorter the intertrial interval, the weaker the visual response of these substantia nigra cells under the nonfixation condition. The response reduction built up over several trials. The 2nd type of response related to the monkey''s fixation of gaze was a response to the offset of a spot of light (mean latency, 131 ms) that the monkey was fixating (fixation-contingent visual off-response). Of 154 substantia nigra cells with some sensory or oculomotor responses, 36 cells (23%) showed this type of response. Many of them also had a nonfixation contingent visual on-response. This contingent off-response was largely suppressed if another spot went off; the response was present only when the fixation spot went off leaving no other overt stimulus. The response became greater as the period from the offset of the fixation spot to the onset of a visual target increased. These substantia nigra cells respond to the appearance of a light spot that the monkey is going to fixate or to the disappearance of a light spot that it was fixating. They may signal the initiation or the termination of visually guided oculomotor behavior.